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Novel self-assembled porous yolk-shell NiO nanospheres with excellent electrochromic performance for smart windows

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Particuology 2024年第1期84卷 72-80页

作者： Baoshun Wang Ya Huang Siming Zhao Run Li Di Gao Hairong Jiang Rufan Zhang Beijing Key Laboratory of Green Chemical Reaction engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing100084China

With the rapid development of optoelectronics,electrochromic(EC)materials(ECMs)with the advan-tages of low power consumption,easy viewing,high contrast ratio,etc have attached more and more attention from the fields of smart windows,electronic billboards,emerging wearable and portable electronics,and other next-generation displays.Nickel oxide(NiO)is a promising candidate for high-performance ECMs because of its neutral-colored states and low cost.However,NiO-based ECMs still face the problem of slow switching speed due to their low electrical conductivity and small lattice spacing.Metal-organic frameworks(MOFs)are promising candidates to fabricate hollow and porous transition metal oxides(TMOs)with high ion transport efficiency,excellent specific capacitance,and electrochemical activities.In this work,porous yolk-shell NiO nanospheres(PYS-NiO NSs)were syn-thesized via a solvothermal and subsequent calcination process of Ni-MOF,which exhibited outstanding EC performance.Because the large specific surface areas and hollow porous nanostructures were conducive to ionic transport,PYS-NiO NSs exhibited a fast coloring/bleaching speed(3.6/3.9 s per one coloring/bleaching cycle)and excellent cycling stability(82%of capacity retention after 3000 cycles).These superior EC properties indicated that the PYS-NiO NSs was a promising candidate for high-performance EC devices.This work provides a new and feasible strategy for the efficient preparation of TMOs ECMs with good EC performance,especially fast switching speed.

关键词： Electrochromic Nickel oxide Metal-organic frameworks Hollow structure Smart windows

Fully integrated and broadband Si-rich silicon nitride wavelength converter based on Bragg scattering intermodal four-wave mixing

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Photonics Research 2024年第3期12卷 I0001-I0010页

作者： VALERIO VITALI THALÍA DOMÍNGUEZ BUCIO HAO LIU JOSÉMANUEL LUQUE GONZÁLEZ FRANCISCO JURADO-ROMERO ALEJANDRO ORTEGA-MOÑUX GLENN CHURCHILL JAMES C.GATES JAMES HILLIER NIKOLAOS KALFAGIANNIS DANIELE MELATI JENS H.SCHMID ILARIA CRISTIANI PAVEL CHEBEN J.GONZALO WANGÜEMERT-PÉREZ ÑIGO MOLINA-FERNÁNDEZ FREDERIC GARDES COSIMO LACAVA PERIKLIS PETROPOULOS Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK 2ElectricalComputer and Biomedical Engineering DepartmentUniversity of PaviaPavia 27100Italy 3Telecommunication Research Institute(TELMA)Universidad de MálagaCEI Andalucı´a TECHE.T.S.I.Telecomunicación29010 MálagaSpain 4School of Science and TechnologyNottingham Trent UniversityNottingham NG118NSUK 5Department of Electrical EngineeringEindhoven University of TechnologyEindhoven 5600 MBThe Netherlands 6Department of Materials Science and EngineeringUniversity of IoanninaIoannina 45110Greece 7Centre de Nanosciences et de NanotechnologiesUniversitéParis-SaclayCNRS91120 PalaiseauFrance 8Advanced Electronics and Photonics Research CenterNational Research Council CanadaOttawaOntario K1A 0R6Canada

Intermodal four-wave mixing(FWM)processes have recently attracted significant interest for all-optical signal processing applications thanks to the possibility to control the propagation properties of waves exciting distinct spatial modes of the same waveguide.This allows,in principle,to place signals in different spectral regions and satisfy the phase matching condition over considerably larger bandwidths compared to intramodal processes.However,the demonstrations reported so far have shown a limited bandwidth and suffered from the lack of on-chip components designed for broadband manipulation of different modes.We demonstrate here a silicon-rich silicon nitride wavelength converter based on Bragg scattering intermodal FWM,which integrates mode conversion,multiplexing and de-multiplexing functionalities on-chip.The system enables wavelength conversion between pump waves and a signal located in different telecommunication bands(separated by 60 nm)with a 3 dB bandwidth exceeding 70 nm,which represents,to our knowledge,the widest bandwidth ever achieved in an intermodal FWM-based system.

关键词： scattering pump modal

A system-on-chip microwave photonic processor solves dynamic RF interference in real time with picosecond latency

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Light(Science & Applications) 2024年第1期13卷 91-102页

作者： Weipeng Zhang Joshua C.Lederman Thomas Ferreira de Lima Jiawei Zhang Simon Bilodeau Leila Hudson Alexander Tait Bhavin J.Shastri Paul R.Prucnal department of electrical and Computer engineering Princeton UniversityPrinceton08544NJUSA NEC Laboratories America Princeton08540NJUSA department of electrical and Computer engineering Queen’s UniversityKingstonK7L 3N6OntarioCanada department of Physics Engineering Physics and AstronomyQueen’s UniversityKingstonK7L 3N6OntarioCanada

Radio-frequency interference is a growing concern as wireless technology advances,with potentially life-threatening consequences like interference between radar altimeters and 5 G cellular networks.Mobile transceivers mix signals with varying ratios over time,posing challenges for conventional digital signal processing(DSP)due to its high latency.These challenges will worsen as future wireless technologies adopt higher carrier frequencies and data rates.However,conventional DSPs,already on the brink of their clock frequency limit,are expected to offer only marginal speed advancements.This paper introduces a photonic processor to address dynamic interference through blind source separation(BSS).Our system-on-chip processor employs a fully integrated photonic signal pathway in the analogue domain,enabling rapid demixing of received mixtures and recovering the signal-of-interest in under 15 picoseconds.This reduction in latency surpasses electronic counterparts by more than three orders of magnitude.To complement the photonic processor,electronic peripherals based on field-programmable gate array(FPGA)assess the effectiveness of demixing and continuously update demixing weights at a rate of up to 305 Hz.This compact setup features precise dithering weight control,impedance-controlled circuit board and optical fibre packaging,suitable for handheld and mobile scenarios.We experimentally demonstrate the processor’s ability to suppress transmission errors and maintain signal-to-noise ratios in two scenarios,radar altimeters and mobile communications.This work pioneers the real-time adaptability of integrated silicon photonics,enabling online learning and weight adjustments,and showcasing practical operational applications for photonic processing.

关键词： processor mixing dynamic

Channel-Feedback-Free Transmission for Downlink FD-RAN:A Radio Map Based Complex-Valued Precoding Network Approach

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China communications 2024年第4期21卷 10-22页

作者： Zhao Jiwei Chen Jiacheng Sun Zeyu Shi Yuhang Zhou Haibo Xuemin(Sherman)Shen School of Electronic Science and engineering Nanjing UniversityNanjing 210023China College of Information Science and Electronic engineering Zhejiang UniversityHangzhou 310058China department of Mathematics and Theories Peng Cheng LaboratoryShenzhen 518000China department of electrical and Computer engineering University of WaterlooWaterlooOntarioN2L 3G1Canada

As the demand for high-quality services proliferates,an innovative network architecture,the fully-decoupled RAN(FD-RAN),has emerged for more flexible spectrum resource utilization and lower network costs.However,with the decoupling of uplink base stations and downlink base stations in FDRAN,the traditional transmission mechanism,which relies on real-time channel feedback,is not suitable as the receiver is not able to feedback accurate and timely channel state information to the transmitter.This paper proposes a novel transmission scheme without relying on physical layer channel feedback.Specifically,we design a radio map based complex-valued precoding network(RMCPNet)model,which outputs the base station precoding based on user *** comprises multiple subnets,with each subnet responsible for extracting unique modal features from diverse input modalities.Furthermore,the multimodal embeddings derived from these distinct subnets are integrated within the information fusion layer,culminating in a unified representation.We also develop a specific RMCPNet training algorithm that employs the negative spectral efficiency as the loss function.We evaluate the performance of the proposed scheme on the public DeepMIMO dataset and show that RMCPNet can achieve 16%and 76%performance improvements over the conventional real-valued neural network and statistical codebook approach,respectively.

关键词： beamforming complex neural networks deep learning FD-RAN

Mitigation of Transients in Capacitor Coupled Substations Using Traditional RLC Filter Techniques

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Journal of Power and Energy engineering 2024年第5期12卷 60-75页

作者： Sinqobile Wiseman Nene Bolanle Tolulope Abe Agha Francis Nnachi department of electrical engineering Tshwane University of Technology eMalahleni South Africa

This article presents an extensive examination and modeling of Capacitor Coupled Substations (CCS), noting some of their inherent constraints. The underlying implementation of a CCS is to supply electricity directly from high-voltage (HV) transmission lines to low-voltage (LV) consumers through coupling capacitors and is said to be cost-effective as compared to conventional distribution networks. However, the functionality of such substations is susceptible to various transient phenomena, including ferroresonance and overvoltage occurrences. To address these challenges, the study uses simulations to evaluate the effectiveness of conventional resistor-inductor-capacitor (RLC) filter in mitigating hazardous overvoltage resulting from transients. The proposed methodology entails using standard RLC filter to suppress transients and its associated overvoltage risks. Through a series of MATLAB/Simulink simulations, the research emphasizes the practical effectiveness of this technique. The study examines the impact of transients under varied operational scenarios, including no-load switching conditions, temporary short-circuits, and load on/off events. The primary aim of the article is to assess the viability of using an established technology to manage system instabilities upon the energization of a CCS under no-load circumstances or in case of a short-circuit fault occurring on the primary side of the CCS distribution transformer. The findings underscore the effectiveness of conventional RLC filters in suppressing transients induced by the CCS no-load switching.

关键词： Capacitor Coupled Substation System Modeling Ferroresonance RLC filters Power electronics Transients Capacitor Voltage Transformers Transmission Lines

High Sensitivity Digital Instantaneous Frequency Measurement Receiver for Precise Frequency Analysis

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Journal of Computer and communications 2024年第1期12卷 177-190页

作者： Bilal Abdulhamed Chien-In Henry Chen department of electrical engineering Wright State University Dayton Ohio USA

There are numerous applications, such as Radar, that leverage wideband technology. However, the presence of noise introduces certain limitations and challenges. It is crucial to harness wideband technology for applications demanding the rapid and precise transmission of diverse information from one point to another within a short timeframe. The ability to report a signal without tuning within the input bandwidth stands out as one of the advantages of employing a digital wideband receiver. As indicated, a digital wideband receiver plays a pivotal role in achieving high precision and accuracy. The primary distinction between Analog and Digital Instantaneous Frequency Measurement lies in the fact that analog Instantaneous Frequency Measurement (IFM) receivers have traditionally covered extensive input bandwidths, reporting one accurate frequency per short pulse. In the contemporary landscape, digital IFM systems utilize high-sampling-rate Analog-to-Digital Converters (ADC) along with Hilbert transforms to generate two output channels featuring a 90-degree phase shift. This paper explores the improvement of sensitivity in current digital IFM receivers. The optimization efforts target the Hilbert transform and autocorrelations architectures, aiming to refine the system’s ability to report fine frequencies within a noisy wide bandwidth environment, thereby elevating its overall sensitivity.

关键词： Digital Wideband Receiver Instantaneous Frequency Measurement (IFM) Receiver

Tunable magneto-Seebeck effect in Co_(2)FeSi/MgO/Co_(2)FeSi heterostructure via optimized interfacial engineering

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 128-135页

作者： Jingyu Li Xianbiao Shi Yurong Jin Le Ma Liuming Wei Chi Zhang Hang Li Peng-Fei Liu International Joint Research Laboratory of New Energy Materials and Devices of Henan Province School of Physics and ElectronicsHenan UniversityKaifeng 475004China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Defence Industry Secrecy Examination and Certification Center Beijing 100089China School of Materials Science and engineering Nanjing University of Science and TechnologyNanjing 210094China department of Network Security Henan Police CollegeZhengzhou 450046China College of electrical engineering Henan University of TechnologyZhengzhou 450001China

Enhancing the tunneling magneto-Seebeck(TMS) ratio and uncovering its underlying mechanism are greatly demanded in spin caloritronics.The magnitude and sign of the TMS effect depend on the type of atom and the stacking order of atoms at the interfaces.Herein,we demonstrate that TMS ratios can be effectively manipulated by altering heterogonous or homogeneous interface through decoration on the CoFeSi(001) surface inserted on the MgO insulating layers.The maximum TMS ratio of pure Co_(2)/O termination is 4565% at 800 K.Notably,the TMS ratio of the FeSi/O termination has two peak values,of which the maximum could reach up to-3290% at 650 K.By comparing two different atom arrangements at the interface,we reveal that the sign and symbol of the TMS ratio can be controlled by the temperature and different atomic configurations at the Co_(2)FeSi/MgO interface.Furthermore,the spin-Seebeck coefficient up to ~150 μV/K is also possible when we select suitable terminations and temperatures.These findings will provide useful insights into how to control the sign and symbol of the TMS ratio and accordingly stimulate the development field of magneto-thermoelectric power and spin caloritronic devices based on the magneto-Seebeck effect in Heusler-based metallic multilayers.

关键词： magneto-Seebeck effect interface spintronics electronic structure spin-Seebeck effect

Theoretical Research on a D-band Traveling Wave Extended Interaction Amplifier

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Chinese Journal of electronics 2024年

作者： Zhongtao CUI Xuesong YUAN Xiaotao XU Dongrui CHEN Yifan ZU Matthew Thomas Cole Qingyun CHEN Yang YAN Terahertz Science and Technology Key Laboratory of Sichuan Province School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of China department of Electronic and electrical engineering University of Bath

A traveling-wave, extended interaction amplifier is herein investigated for use in millimeter-wave and terahertz amplification sources. By placing engineered extended interaction cavities between the traveling wave structures, higher gain is obtained with a shorter high frequency circuit, compared with conventional traveling wave tubes architectures. The bandwidth of the device is significantly increased relative to extended interaction klystrons. A Dband beam wave interaction circuit of 26 mm long has been designed. Particle in cell simulations at 21.5 kV operating voltage, 0.3 A beam current, and 5 mW input power show that the maximum output power reaches 351 W, with a gain of 48.4 dB and 3-dB bandwidth of 1.42 GHz.

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Design of Protograph LDPC-Coded MIMO-VLC Systems with Generalized Spatial Modulation

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China communications 2024年第3期21卷 118-136页

作者： Dai Lin Fang Yi Guan Yongliang Mohsen Guizani School of Information engineering Guangdong University of TechnologyGuangzhou 51006China The State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710126China School of electrical and Electronic engineering Nanyang Technological UniversitySingapore department of Machine Learning Mohamed Bin Zayed University of Artificial Intelligence(MBZUAI)Abu DhabiUnited Arab Emirates

This paper investigates the bit-interleaved coded generalized spatial modulation(BICGSM) with iterative decoding(BICGSM-ID) for multiple-input multiple-output(MIMO) visible light communications(VLC). In the BICGSM-ID scheme, the information bits conveyed by the signal-domain(SiD) symbols and the spatial-domain(SpD) light emitting diode(LED)-index patterns are coded by a protograph low-density parity-check(P-LDPC) code. Specifically, we propose a signal-domain symbol expanding and re-allocating(SSER) method for constructing a type of novel generalized spatial modulation(GSM) constellations, referred to as SSERGSM constellations, so as to boost the performance of the BICGSM-ID MIMO-VLC systems.Moreover, by applying a modified PEXIT(MPEXIT) algorithm, we further design a family of rate-compatible P-LDPC codes, referred to as enhanced accumulate-repeat-accumulate(EARA) codes,which possess both excellent decoding thresholds and linear-minimum-distance-growth property. Both analysis and simulation results illustrate that the proposed SSERGSM constellations and P-LDPC codes can remarkably improve the convergence and decoding performance of MIMO-VLC systems. Therefore, the proposed P-LDPC-coded SSERGSM-mapped BICGSMID configuration is envisioned as a promising transmission solution to satisfy the high-throughput requirement of MIMO-VLC applications.

关键词： bit-interleaved coded modulation generalized spatial modulation multiple-input multipleoutput protograph LDPC codes visible light communication